干旱指标在陕西省应用的敏感性分析

 利用陕西省1961—2005年各气象站旬气象资料、33个农气旬报站土壤相对湿度及2001年6月13日NOAA-16极轨气象卫星资料,分析了降水距平百分率、Z指数、Palmer干旱指数、土壤相对湿度对干旱的发生、发展、变化的敏感性,描述干旱发生的范围、程度的差异,并将反映出的旱情与同时段用遥感监测得到的旱情进行比较。结果表明:降水距平百分率、Z指数对旱情的变化具有很高的敏感性,各干旱指标都能反应出区域内干旱的发生,但各指标反映出的干旱程度和范围不同;与同时段遥感监测得到的旱情相比,遥感监测的旱情更加细致,并与地表状况有关。干旱是一个累积过程,同时与影响对象有密切关系,使用干旱指标分析旱情时需要根据受旱对象选用不同的干旱指标,综合考虑前期的水分状况与旱情发生、发展有关的因素。

Sensitivity Analysis of Drought Indices used in Shaanxi Province

It has been analyzed the sensitivity of precipitation anomaly, Z-index, Palmer drought index and soil relative moisture to drought occurrence, development and evolution, based on the ten-day precipitation data from meteorological stations, soil relative moisture data from agrometeorological stations in Shannxi province during 1961—2005, and the NOAA-16 polar orbit meteorological satellite data on June 13, 2001. The results showed that precipitation anomaly and Z-index have high sensitivity to drought evolution; they all can reflect the drought occurrence except the different intensity and extension reflected. Compared with the monitoring drought regime by remote sensing at the same time, the monitoring data are more detailed, showing relation with the coverage of the ground surface. Suitable drought indices should be selected in drought analysis against the object, and combined with consideration of moisture status in prophase and the relative factors with drought development.